A technological option for avoiding the impacts of rising carbon dioxide on the Earth's climate is to capture the carbon dioxide that would otherwise be emitted from stationary industrial sources, such as power plants, and store the CO2 in geological reservoirs, a process known as carbon capture and storage (CCS). A related option is to capture carbon dioxide directly from the atmosphere, a process known as direct air capture (DAC), followed also by storing the CO2 in geological reservoirs.
Effective methods and systems for detecting leakage from geological CO2 sequestration sites as well as quantifying the efficiency of CCS systems can be critical to ensuring that objectives of the sequestration process are being met. Proper accounting of both leakage and capture efficiency is also required under the United Nations Framework Convention on Climate Change. Additionally, the U.S. DOE has specified a target of 0.01% per annum for the maximum leak rate from geologic storage sites. For a large-scale storage site containing 10 to 100 Mton CO2, this corresponds to a CO2 leakage rate of 100 to 1000 tons CO2 per year or 0.032 to 0.32 g CO2 per second. Detection of such tiny leaks above a much larger varying (natural and anthropogenic) background is a technological challenge that is addressed by one or more implementations of the current subject matter.